While the etiology of endometriosis is likely multifactorial, the long-range goal of this project is to understand a recently identified component to endometriosis due to developmental estrogen programming. The data linking developmental DES exposure in humans and our preliminary data in mice have led to the hypothesis: Developmental xenoestrogen exposure programs the fetus by altered DNA methylation and exacerbates endometriosis in adulthood. Three specific aims are proposed. Specific Aim 1. Does developmental exposure to bisphenol A, genistein and ethinyl estradiol at current human exposure levels exacerbate endometriosis in adulthood. We have shown that developmental DES exposure increases cell proliferation in endometriotic lesions in a mouse model of surgically induced endometriosis and results in larger lesions relative to control mice. After developmental exposure to bisphenol A, genistein, ethinyl estradiol or DES, we will surgically induce endometriosis in adult mice. Four weeks later, we will measure lesion weight, cell proliferation, apoptosis and angiogenesis. Specific Aim 2. Does developmental xenoestrogen exposure program gene expression in endometriotic lesions? We have shown that developmental DES exposure alters the expression of extracellular matrix and adhesion molecules in endometriotic lesions. After developmental xenoestrogen exposure and surgical induction of endometriosis in adulthood, we will use RNA isolated from endometriotic lesions to probe Illumina mouseref 8 microarrays. Specific Aim 3. Does developmental xenoestrogen exposure alter DNA methylation of genes in endometriotic lesions. Many genes in human endometriotic tissue have recently been identified with altered DNA methylation. In a preliminary study, we have shown that exposure to DES or ethinyl estradiol during development alters the DNA methylation profile in eutopic endometrium. We will use mouse methylated CpG island amplification (MCA) as a global approach to screen mouse CpG islands for altered DNA methylation. This project has the potential to lead to new therapeutics for treatment of endometriosis with drugs that alter DNA methylation. In a broader context, this project is likely to identify candidate genes and their proteins that can be used as targets for novel therapeutics. Further, a causal relationship between xenoestrogen exposure and exacerbation of endometriosis in adulthood represents a prime target for intervention by reducing exposure to these environmental chemicals. PUBLIC HEALTH RELEVANCE: A causal relationship between fetal exposure to estrogenic environmental chemicals and endometriosis in adulthood represents a prime target for intervention by reducing exposure to these environmental chemicals and to perhaps decrease the severity of endometriosis. Further, this project has the potential to lead to new therapeutics for treatment of endometriosis with drugs that alter DNA methylation. In a broader context, this project is likely to identify candidate genes and their proteins that can be used as targets for novel therapeutics in the treatment and possible cure of endometriosis.